How to set and get environment variables using Python

A short post on setting environment variables using Python.

If you want to get and set environment variables using Python, simply use the relevant methods from os. To set an environment variable, do this:

import os

os.environ['SOME_ENV_VARIABLE'] = 13.5

And to access an environment variable, there are actually a number of different ways. All these three are essentially the same:

os.getenv('SOME_ENV_VARIABLE')
os.environ.get('SOME_ENV_VARIABLE')
os.environ('SOME_ENV_VARIABLE')

For the final one (os.environ('SOME_ENV_VARIABLE')), if the variable doesn’t exist, it’ll return a KeyError, whereas the first two will just return None in that case.